On Sun, Nov 27, 2016 at 01:19:54PM +0000, Mel Gorman wrote: > While it is recognised that this is a mixed bag of results, the patch > helps a lot more workloads than it hurts and intuitively, avoiding the > zone->lock in some cases is a good thing. > > Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> This seems like a net gain to me, and the patch loos good too. Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> > @@ -255,6 +255,24 @@ enum zone_watermarks { > NR_WMARK > }; > > +/* > + * One per migratetype for order-0 pages and one per high-order up to > + * and including PAGE_ALLOC_COSTLY_ORDER. This may allow unmovable > + * allocations to contaminate reclaimable pageblocks if high-order > + * pages are heavily used. I think that should be fine. Higher order allocations rely on being able to compact movable blocks, not on reclaim freeing contiguous blocks, so poisoning reclaimable blocks is much less of a concern than poisoning movable blocks. And I'm not aware of any 0 < order < COSTLY movable allocations that would put movable blocks into an HO cache. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>